Welcome aboard. Other than swapping the emitter to the tint of your choice, I wouldn't mod the D40A. It has one of the smoothest beams I can think of. This is probably my most used light. Dedoming it would take away much of the usefulness for me as its as it has the perfect balance of flood and throw for general usage.
I would get the cold tint version with the intent of swapping the emitter. Mine had a xml2 u2 with what I would guess a 1A tint. Great emitter to dedome for a big thrower light. Then buy an xm-l2 in the tint of your choice. Also get a copper base (Noctigon or Sinkpad). Here is a great thread to help you find the emitter you want and the best price. This ansi color chart with Cree tint codes overlaid is from it:
